Method of manufacturing parts of thin form by fritting



May 15, 1 2 J. CARTIER ETAL 3,034,178

METHOD OF MANUFACTURING PARTS OF THIN FORM BY FRITTING Filed July 15, 1960 INVENTORS J BAN ART 1BR.

BYFELIX BOULCH A T TO/PNEYS I ma,

grates Patented May 15, 1962 3 034 17s METHOD or MANUFACTURE; PARTS oF TEEN FORM BY FRITTING Jean Cartier, Beauchamp, and Felix Le Boulch, Franeon The pressent invention has for its object a method of manufacturing by fritting, by means of an automatic press, parts of thin form in which the rate of comprmsion of the metal powder is substantially constant at all points of the part.

When a metal powder is compressed on an automatic press in order to manufacture fritted parts, a certain number of rules must be observed, the most important of which is that the degree of compression, defined as the ratio of the density of the initial powder to the density of the moulded part, must have a value which is as constant as possible at all points of the part.

In order to make parts of simple shapes, vertical compression is used, the space between the die or dies and the die mould, which is initially filled by the metal powder, having dimensions in the vertical direction which are in a precise ratio, equal to the desired degree of compression, to the dimensions of the part to be made, so as to obtain a homogeneous compressed part.

When it is endeavoured to obtain a thin spherical cup or a cone, for example, it is not possible to use this method. This would therefore require either multiple dies or devices which can only be used with difficulty on automatic machines.

The present invention has for its object a method of compressing metal powders for manufacturing parts of thin form by fritting by means of a die and a die mould, characterised by the fact that there is imparted either to the die or to the die mould a rotary movement the result of which is as it were, to fiuidify or flow the powder, which then fills the space between the die and the die mould homogeneously, the powder being then compressed between the die and the die mould.

The method forming the object of the invention will now be described with reference to the embodiment given in the drawings.

FIGURE '1 is an axial section of the part to be made;

FIGURE 2 is an axial section showing the introduction of the powder into the die mould;

FIGURE 3 is an axial section showing the penetration of the rotary die into the powder;

FIGURE 4 is an axial section showing the stage of operation where the powder is distributed homogeneously in the space left for it between the die and the die mould;

FIGURE 5 is an axial section showing the final compression carried out by the die;

FIGURE 6 is an axial section showing the ejection of the moulded part from the die mould.

To manufacture a fritted part 1 such as that shown in FIGURE 1, a certain quantity of metal powder is poured into a die mould 3 of conical shape (FIGURE 2). When the top die 4 penetrates as it rotates into the heap of powder 2 (FIGURE 3), it carries the powder along and the powder then becomes fluid or flows and is disposed homogeneously between the die and the die mould (FIGURE 4).

' The top die 4 can then continue its stroke with or without rotation until the degree of compression desired' for the part 1 is obtained (FIGURE 5).

When the pressure of the die becomes considerable and if the die is rotated by friction, the rotation is stopped and the die terminates the compression. This stopping of the die is almost necessary practically speaking, but not theoretically, and it would be possible to imagine the use of a ball stop sulficiently strong to permit continuous rotation of the die without jamming, even with the force of compression.

After the top die 4 has completed the compression to the degree desired, it is withdrawn and an ejector 5 removes the compressed part 1 from the die mould 3(FIG- URE 6).

Of course, modifications could be made in the method described above without thereby departing from the scope of the invention. In particular, instead of imparting a rotary movement to the die, said movement could be imparted to the die mould. Likewise, the descending movement. of the die could be replaced by an ascending movement of the die mould. These four movements could be applied in :all their possible combinations to these two elements, provided that the resultant movements are a relative rotation of oneof the elements with respect to the other and a penetration of the die into the die mould.

What we claim is:

1. In a method of manufacturing parts of'thin form from metal powder by means of a die mould and a die smaller than the die mold prior to sintering, the steps of pouring the metal powder into the die mold, moving the die into the die mold with relative rotation between the die and the die mold at speeds preserving the powder characteristics of the metal powder whereby the metal particles flow into a homogeneous thickness of metal powder around the die in the die mold and then compressing the powder by further penetration of the die into the References Cited in the file of this patent UNITED STATES PATENTS 2,395,295 Rowland Feb. 19, 1946 2,398,227 Hubbert Apr. 9, 1946 2,399,592 Bradshaw Apr. 30, 1946 3 P g 

